CH27 Male Reproductive System — Condensed Exam Notes

A comprehensive set of vocabulary flashcards covering anatomical structures, physiological processes, hormones, and clinical terms related to the male reproductive system presented in Chapter 27.

Primary Sex Organs (Gonads)

Organs that produce gametes; testes in males, ovaries in females.

Secondary Sex Organs

Structures other than gonads required for reproduction (e.g., ducts, glands, penis in males).

Secondary Sex Characteristics

Features that distinguish the sexes and aid mate attraction (e.g., facial hair, voice pitch).

Scrotum

Pouch of skin, muscle, and connective tissue that houses the testes outside the body.

Perineum

Diamond-shaped region between thighs bordered by pubic symphysis, ischial tuberosities, and coccyx.

Perineal Raphe

Medial seam on scrotal surface marking the internal septum.

Spermatic Cord

Bundle containing ductus deferens, blood/lymph vessels, and nerves that passes through the inguinal canal.

Cremaster Muscle

Strips of skeletal muscle that raise or lower testes to regulate temperature.

Dartos Muscle

Subcutaneous smooth muscle that wrinkles scrotal skin to conserve heat.

Pampiniform Plexus

Venous network that cools arterial blood entering the testes via counter-current heat exchange.

Testes

Combined endocrine and exocrine glands producing testosterone and sperm.

Tunica Albuginea

White fibrous capsule surrounding each testis.

Seminiferous Tubules

Highly coiled ducts in testicular lobules where spermatogenesis occurs.

Sustentacular (Sertoli) Cells

Supporting cells in seminiferous tubules that nourish germ cells and form the blood-testis barrier.

Interstitial (Leydig) Cells

Cells located between seminiferous tubules that secrete testosterone.

Blood–Testis Barrier (BTB)

Tight junctions between Sertoli cells that isolate developing sperm from the immune system.

Rete Testis

Network that collects sperm from seminiferous tubules before they enter efferent ductules.

Efferent Ductules

Ciliated ducts transporting sperm from rete testis to epididymis.

Epididymis

Coiled duct on posterior testis where sperm mature and are stored (fertile 40-60 days).

Ductus (Vas) Deferens

45 cm muscular tube carrying sperm from epididymis to the ejaculatory duct.

Ampulla of Ductus Deferens

Terminal widened portion of ductus deferens behind the bladder.

Ejaculatory Duct

2 cm duct formed by ductus deferens and seminal vesicle that empties into urethra.

Male Urethra

18 cm passage shared by urinary and reproductive systems; prostatic, membranous, spongy regions.

Seminal Vesicles

Paired glands posterior to bladder; contribute about 60 % of semen (fructose-rich fluid).

Prostate Gland

Gland surrounding urethra below bladder; secretes thin, milky fluid (≈30 % of semen).

Bulbourethral (Cowper) Glands

Small glands near penile bulb producing pre-ejaculate that lubricates and neutralizes urethra.

Benign Prostatic Hyperplasia (BPH)

Non-cancerous enlargement of prostate that obstructs urine flow.

Prostate Cancer

Common male cancer often detected by elevated PSA levels or digital rectal exam.

Penis

Copulatory organ delivering semen to female tract; consists of root, shaft, and glans.

Corpus Spongiosum

Single erectile body surrounding the spongy urethra on ventral penis.

Corpora Cavernosa

Pair of erectile bodies dorsolateral to urethra; main tissue engorged during erection.

Lacunae

Blood sinuses within erectile tissues that fill during erection.

Puberty

Period when reproductive system is activated by gonadotropins; marks onset of fertility.

Gonadotropin-Releasing Hormone (GnRH)

Hypothalamic hormone stimulating anterior pituitary to release FSH and LH.

Follicle-Stimulating Hormone (FSH)

Pituitary hormone prompting Sertoli cells to secrete androgen-binding protein (ABP).

Luteinizing Hormone (LH)

Pituitary hormone stimulating Leydig cells to secrete testosterone.

Androgen-Binding Protein (ABP)

Protein from Sertoli cells that binds testosterone to promote spermatogenesis.

Inhibin

Hormone from Sertoli cells that selectively inhibits FSH to regulate sperm production.

Spermatogenesis

Process in seminiferous tubules producing haploid sperm cells from germ cells.

Spermiogenesis

Final transformation of spermatids into motile spermatozoa (tail growth, cytoplasm loss).

Spermatozoon

Mature male gamete consisting of a head (nucleus, acrosome) and tail for motility.

Acrosome

Enzyme-filled cap on sperm head that helps penetrate the egg.

Midpiece of Sperm

Tail segment packed with mitochondria supplying ATP for movement.

Semen

Mixture of sperm and glandular secretions expelled during ejaculation (2–5 mL).

Seminogelin

Sticky fibrin-like protein formed from proseminogelin by a prostate enzyme to clot semen.

Serine Protease (PSA)

Prostatic enzyme that liquefies semen by breaking down seminogelin after ejaculation.

Sperm Motility Requirements

Elevated pH (≈7.5) and fructose-derived ATP from seminal fluid.

Emission

First stage of ejaculation where sympathetic peristalsis moves sperm into urethra with secretions.

Expulsion

Second stage of ejaculation involving muscular contractions that eject semen from urethra.

Detumescence

Return of the penis to a flaccid state during the resolution phase.

Refractory Period

Post-ejaculatory interval when another erection or orgasm is temporarily impossible.

Male Climacteric (Andropause)

Age-related decline in testosterone and reproductive function, often after age 50.

Erectile Dysfunction (Impotence)

Inability to achieve or maintain an erection sufficient for intercourse.

PDE5 Inhibitors (e.g., Viagra)

Drugs that prolong cGMP action to sustain penile blood flow and erection.

Cremasteric Reflex

Elevating response of testes when inner thigh is stroked (temperature control mechanism).

Trabeculae

Connective tissue partitions between lacunae within erectile bodies.

Deep Artery of Penis

Branch of internal pudendal artery that dilates to fill corpora cavernosa during erection.

Helicine Arteries

Small branches of deep penile artery that open into lacunae during erection.

Masters & Johnson Cycle

Four phases of sexual response: excitement, plateau, orgasm, resolution.

Emission vs. Orgasm

Emission is movement of semen into urethra; orgasm is the overall pleasurable climax often accompanying ejaculation.

Basal Body of Sperm

Indentation at base of nucleus where flagellum attaches.

Prostaglandins in Semen

Compounds that may thin cervical mucus and stimulate uterine contractions to aid sperm transport.

Dihydrotestosterone (DHT)

Potent androgen derived from testosterone that promotes hair growth and other secondary traits.